Communication system



1942. w. M. KOLEHMAINEN 8 COMMUNICATION SYSTEM Filed June 14, 1941 2 Sheets-Sheet l 1 Nov. 17, 1942. w. M. KOLEHMAINEN 2,302,498

COMMUNICATION SYSTEM Filed June 14, 1941 2 Sheets-Shee t 2 WI E r w m- 135 l 1; 1 ikwmzaza flzkaif/wzemzlzzeza Patented Nov. 17, 1942 COMMUNICATION SYSTEM Waino lVI. Kolehmainen, Winnetka, 111., assignor to Webster Electric Company, Racine, Wis., a

corporation of Delaware Application June 14, 194-1, Serial No. 398,016

19 Claims.

The present invention relates to communication systems and more particularly to intercommunicating systems of the loudspeaking type. In one type of intercommunicating system a plurality of stations are each provided with a receiver, a microphone, an amplifier, to the input of which the microphone is connected, and station selector switches for connecting the output of the amplifier to the receivers of other stations. The arrangement is such, therefore, that communication between stations is carried on in separate channels, each of which includes a microphone and amplifier at one station and a receiver at another station. These systems have also incuded stations of a second type having receivers adapted selectively to be connected to the output of an amplifier, so that they can receive messages from, but cannot send messages to, stations of the first type.

It is an object of the present inventionto provide a system including one or more stations of the first type and one or more stations of the second type, wherein it is possible to carry on communication in both directions not only between stations of the first type, but also between stations of the first and second types.

A further object of the present invention is to provide an arrangement of the type described, wherein the stations of the first type are provided with combined station selector and communication control switches for selecting and controlling the direction of communication with stations of the second type.

Another object of the present invention is to provide an arrangement of the type described, wherein stations of the first type are provided with separate station selector and communication control switches, thereby to make uniform the manner of selecting stations of both types.

' A further object of the invention resides in the particular construction and arrangement of the communication control switches.

Other objects and advantages of the present invention will become apparent from the ensuing description, in the course of which reference is had to the accompanying drawings, in which:

Fig. l is a diagrammatic representation of one embodiment of the invention; and

Fig. 2 is a similar representation Of another embodiment.

Referring now to Fig. 1, the communication system illustrated therein is shown to include two stations i and 2 of a first type and two stations each provided with amplifiers II and I2, microphones .I3 and I4 connected directly to the inputs of the amplifiers, loudspeaking receivers I5 and .It connected to interstation circuits I1 and I8 individual .to the two stations, and a number of station selector switches, to which reference will be had shortly, for connecting the outputs of the amplifiers .to other stations. Station I is provided with .a station selector switch I9 for connecting the output of amplifier vII to the circuit I8 individual to station2, .and a second station selector switchZD for connecting the output of the amplifier to an interstation circuit 2| individual to a third station (not shown). Station 2 is provided with a station selector switch 22 .for connecting the output of amplifier I2 to themtel-station line I! individual to station I, and a station selector switch 23 for connecting the output of the amplifier to the third station. The interstation conductors I! and I8 also extend to the third station, whereby the third station may call stations I and 2.

The system thus far described is of a type known to the art. An improved system of this character is disclosed and claimed in the copending application of Richard H. Campbell, application Serial No. 343,390, assigned to the assignee of the instant application.

Stations 3 and 4 have loudspeakers utilizable both as receivers and microphones that are connected to interstation circuits 24 and 25, respectively, individual to the two stations. These interstation circuits lead to both stations I and 2, and "in accordance with the present invention the latter stations are provided with combined station selector and communication-control switches, whereby communication may be carried on in both directions between the two types of stations. Station I is provided with a combined station see lector and communication control switch 21 to be used when communication is desired with station 3, and a similar switch 28 for use when communication is desired with station 4.

Switch 2? comprises a first switch t 'connected to the output of the amplifier and a second switch 30 connected to the input of the amplifier. The two switches are operable simultaneously and normally occupy positions wherein the circuits controlled thereby are all open, as indicated in Fig. 1. Switch TI is operable into oneposition wherein the interstation line 24 is connected to the output of the amplifier so that messages may be transmitted from station I to station 3.

3 and 4 of a second type. Stations I and 2 are 55 The switch is operable into another position wherein the interstation circuit is connected to the input of the amplifier, and the output of the amplifier is connected to the receiver I5, whereby messages may be transmitted from station 3 to station I. It is preferred that the amplifier II and other amplifiers at stations similar to station I be adjusted as described in the previously referred to application of Richard H. Campbell, to prevent undesired howling when the receiver I is connected to the output and the receiver-microphone at station 3, or other similar station, is connected to the input of the ampifier.

The first of the two positions of the switch referred to is the middle position, at which time it may be noted that the switch 29 connects the output of the amplifier directly to interstation line 25, and switch 35 remains in circuit opening position. The second of the two positions referred to is the down position, in which it may be noted the switch 35 connects the interstation circuit 24 to the input of the amplifier and switch 29 connects the output of the amplifier to the receiver i5. The switch is preferably biased by a spring 3I to return from its down to its middle position, so that in case it is desired to call station 3 at the same time that other stations are called, it is easy to operate the switch to the calling position wherein it is adapted to remain. The switch 23, as already indicated, corresponds in construction and arrangement to switch TI. 1

It is believed sufficient, therefore, to note simply that it comprises two simultaneously operable switches and 33 corresponding to the switches and of switch 21,

Station 2 is similarly provided with a pair of station selector and communication control switches 35 and 35, the former being associated with station 3 and the latter with station 4. The two switches comprise pairs of switches 3'1, 38 and 39, corresponding in construction and arrangement with the pairs of switches 29 and 30 of switch 2! at station I.

In operation, the amplifiers II and I2 may either be normally operative or be rendered operative upon closure of a suitable power control switch. In case station I desires to communicate with station 2, it is necessary for the operator at station I to render operative the amplifier and close the selector switch I9. When this is done,

the output of amplifier II is connected to the receiver I5 at station 2 through the selector switch I9 and the interstation circuit I8 individual to station 2. The operator then speaks into the microphone I3 and the message is received at station 2. To respond to a call, the operator at station 2 must render operative the amplifier I2, if the same is not already in operation, and close selector switch 22. Thisconnects the output of amplifier I2 to the interstation circuit I'I individual to station I, so that messages transmitted through the microphone and amplifier at station 2 are heard in the receiver I5 at station I. While only two stations of this type have been illustrated, it is contemplated that the system may comprise more than two stations.

in case the operator at station I should desire to communicate with station 3. the combined selector and communication control switch 21 is operated from its normal into its middle position. As already described, this connects the interstation circuit 24 and the loudspeaker at station 3 to the output of the amplifier, so that messages may be transmitted from station I to station 3 through the microphone I3, amplifier II, switch 29 and interstation circuit 24. To receive an answer from station 3, it is necessary for the switch 21 to be operated into its lowermost position. The loudspeaker at station 3 is used as a microphone and it is connected to the input of the amplifier through itnerstation circuit 24 and switch blades 30. At the same time the loudspeaker I5 at station I is connected to the output of l the amplifier II through switch blades 29 and the circuit II.

Station I may communicate with station 4 in the same way by use of the combined station selector and communication control switch 28, and station 2 may communicate with stations 3 and 4 in the same way by use of the switches 35 and 36 thereat.

It is contemplated also that a system may include one station of the type of stations 3 and s or any desired number, and that the stations may be connected to any desired number of stations of the character of stations I and 2. In the instant embodiment the two stations 3 and 4 have been shown as included in circuit with stations I and 2 only, but they may be placed in circuit with other stations similar to stations I and 2 by extending the interstation conductors individual thereto to the other stations.

The embodiment of the invention illustrated in Fig. 2 is similar to that of Fig. 1 except that stations of the second type, namely, stations 3 and 4, are placed in communication with stations of the first type, that is, with stations like I and 2, by means of separate station selector and communication control switches. In view of the similarity between the two systems, it is believed that the description will be simplified by indicating like parts with like reference characters and by concentrating on the difference between the two circuits.

Station I is provided with station selector switches 43 and 44 for selecting stations 3 and 4, respectively, and with communication control switches 45 and 46 for controlling the direction of communication with these two stations, respectively. Communication control switch 45 is of a two-position type, and includes a pair of switches 47 normally in circuit opening position but operable to a position to connect the output of amplifier I I to the receiver I5 when the selector switch 43 is closed. The switch 45 includes a second pair of switches 48 normally connecting the interstation circuit 24 to the selector switch 43 and operable in its second position to connect the interstation circuit to the input of the amplifier. The switch is biased to return from its second to its first position by a spring 49.

Switch 45 associated with station 4 is constructed and arranged identically with switch 45. It comprises two pairs of switches 53 and 5I corresponding to the pairs of switches 41 and 48. Station 2 is similarl provided with selector switches 53 and 54 for selecting stations 3 and 4, respectively. It is also provided with communication control switches 55 and 56 for controlling the direction of communication with these two stations. Switch 55 comprises the simultaneously operable pairs of switches 51 and 58, and switch 55 comprises the simultaneously operable pairs of switches 59 and 60.

The operation of the system of Fig. 2, in so far as communication between stations I and 2 and stations similar thereto is concerned, corresponds identically with that of Fig. 1, so that it is deemed unnecessary to repeat the description thereof.

In case station I desires to communicate with station 3% the operator at station I first cl'oses selector switch 43. Whenthis i's done, the two stations-- are connected for communication from stationi to station 3- as microphone I3 is connected to the input of the amplifier andinter-- stat circuit 24 is connected to-th'eoutput ofthe amplifier through selector switch it and switch blades 53- in their normal or uppermost position. To receive an answer from station 3, the communication control switch 45' isoperated to its lowermost position. When so operated, the interstation circuit is connectedto the input'of the amplifier and the output of the amplifieris connectedto the loudspeaker t5 through the stationsel'ector switch-and switch-blades 4 L In the: event station I desirestocommunicate withstation 4, the operation described above isfollowed, with the exception that switches M and 45 are operated.

Incase station 2 desiresto communicate with stations 3 or 4, the operation described above is repeated, using the proper station selector and communication control switches at station 2.

The advantage of the lastdescribed arrange-- ment is that in case it is desired tocall a num-- ber of or all stations from one station, as from station I, it is necessary only to operate the station selector switches.

Whiietwo embodiments of the invention have been illustrated and described, it should beunderstood that the invention is susceptible of other and further modifications and that the specific detailed description of the embodiments is not intended to be limitative of the lI1V8I1-- tion' exceptin so far as set forth in the accompa-nying' claims,

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1-. In an intercommunicating system, the com- 'oinationincluding, a first station having. an amplifier, a microphone connected to the input ofthe amplifier, a receiver and a communication controlswitch, a second station having a device utilizable both as a receiver and a microphone, and. means including said communication control switch and circuit controlled thereby for selectively connecting said device to the inputand' output ofthe amplifier and for connecting said receiver to the output of the amplifier when said device is connected to the input,

2, Inan intercommunicating system, the com-- bination including, a first station having an amplifier, amicrophone connected to the input of the amplifier, a receiver and a communication control switch-,- asecond station having a device utilizable both as a receiver and a microphone, and means including said communication control switch and circuits controlled thereby for selectively connecting said device to the input and output of the amplifier and for connecting said receiver to the output of the amplifier when said device is connected to the input, said communication control switch being biased to return to a position wherein said device is connected to the output of the amplifier,

3. In an intercommunicating system, the combination including, a first station having an amplifier, a microphone connected to the input of the amplifier, a receiver and a communication. control switch, a second station having a device" utilizable both as a receiver and a microphone,- and means including said. communication control switch and circuits controlled thereby for selectively connecting said device to the input 7 and output of the amplifier and for connecting said receiver to the'output of the amplifier when said device is connected to the input, said communi'cation control switch normally occupying a position wherein the circuits controlled thereby are all open.

4. In an intercommunicating system, the combination including, a first station having an amplifier, a microphone connected to the input of the amplifier, a receiver and a plurality of station selector and communication control switches, a plurality of other stations each having a device utilizable both as a receiver and microphone, circuits connecting each of said sta- 1 tions" to one of said communication control switches, and means including circuits controlled by each of said communication control switches for selectively connecting the device associated therewith to the input and output of the ampliflerand for connecting the receiver to the output of the amplifier when the device is connected to the input.

5. In an intercommunicating system, the combination including, a first station having an amplifier, a microphone connected to the input of the amplifier, a receiver and a plurality of station selector and communication control switches, a plurality of other stations each having a device utilizable both as a receiver and microphone, circuits connecting each of said stations to one of said communication control switches, and means including circuits controlled by each of said communication control switches for selectively connecting the device associateo therewith to the input and output of the ampli-v fi'er' and for connecting the receiver to the output of the amplifier when the device is connected to the input, said station selector and communication control switches being biased to return to a position wherein said device is connected to the output of the amplifier.

6-. In an intercommunicating system, the combination including, a first station having an amplifier, a microphone connected to the input of the amplifier, a receiver and a plurality of station selector and communication control switches, a plurality of other stations each having a device utilizable both as a receiver and microphone, circuits connecting each of said stations to one of said communication control switches, and means including circuits controlled by each of said communication control switches for selectively connecting the device associated therewith to the input and output of the amplifier and for connecting the receiver to the output of the amplifier when the device is connected to the input, said station selector and communication control switches normally occupying positions wherein the circuits controlled thereby are all open.

7. In an intercommunicating system, the combination including, a first station having an amplifier, a microphone connected to the input of the amplifier, a receiver and a plurality of station selector and communication control switches, a plurality of other stations each having a device utilizable both as a receiver and microphone, circuits connecting each of said stations to one of said communication control switches, and means including circuits controlled by each of said communication control switches for selectively connecting the device associated therewith to the input and output of the amplifier and for connecting the receiver to the output of the amplifier when the device is connected to the input, said station selector and communication control switches normally occupying positions wherein the circuits controlled thereby are all open and being biased to return positions wherein said devices are connected to the output of the amplifier from positions wherein the receivers are connected to the output and the devices to the input of the amplifier.

8. In an intercommunicating system of the type including a plurality of stations each including a receiver connected to an interstation circuit individual thereto, an amplifier, a microphone connected to the input of said amplifier and station selector switches for connecting the output of the amplifier to the circuits individual to other stations, the combination including, a station including a device utilizable both as a receiver and a microphone connected to a line individual thereto leading to said plurality of stations, switch means and circuits controlled thereby at said plurality of stations for selectively connecting said device to the input and output of said amplifier and for connecting the receiver at the station to the output of the amplifier when the device is connected to the input.

9. In an intercommunicating system of the type including a plurality of stations each including a receiver connected to an interstation circuit individual thereto, an amplifier, a microphone connected to the input of said amplifier and station selector switches for connecting the output of the amplifier to the circuits individual to other stations, the combination including, a plurality of other stations each including a device utilizable both as a receiver and microphone connected to a line individual thereto leading to said first mentioned plurality of stations, separate switch means at each of said first mentioned plurality of stations associated with the lines individual to the second mentioned plurality of stations, and circuits controlled thereby for selectively connecting the device connected to the line to the input and output of the amplifier and for connecting the receiver at the station to the output of the amplifier when the device is connected to the input.

10. In an intercommunicating system of the type including a plurality of stations each including a receiver connected to an interstation circuit individual thereto, an amplifier, a microphone connected to the input of said amplifier and station selector switches for connecting the output of the amplifier to the circuits individual to other stations, the combination including, a station including a device utilizable both as a receiver and a microphone connected to a line individual thereto leading to said plurality of stations, switch means and circuits controlled thereby at said plurality of stations for selectively connecting said device to the input and output of said amplifier and for connecting the receiver at the station to the output of the amplifier when the device is connected to the input, said switch means normally occupying a position wherein the circuits controlled thereby are all open.

11. In an intercommunicating system of the type including a plurality of stations each including a receiver connected to an interstation circuit individual thereto, an amplifier, a microphone connected to the input of said amplifier and station selector switches for connecting the output of the amplifier to the circuits individual to other stations, the combination including, a

plurality of other stations each including a device utilizable both as a receiver and microphone connected to a line individual thereto leading to said first mentioned plurality of stations, separate switch means at each of said first mentioned plurality of stations associated with the lines individual to the second mentioned plurality of stations, and circuits controlled thereby for selectively connecting the device connected to the line to the input and output of the amplifier and for connecting the receiver at the station to the output of the amplifier when the device is connected to the input, each of said switch means normally occupying a position wherein the circuits controlled thereby are open.

12. In an intercommunicating system, the combination including, a first station having an amplifier, a microphone connected to the input of said amplifier, a receiver, a station selector switch and a communication control switch, a second station having a device utilizable both as a microphone and a receiver, and means including said communication control switch and station selector switch and circuits controlled thereby for selectively connecting said device to the input and output oi said amplifier and for connecting said receiver to the output of said amplifier when said device is connected to the input.

13. In an intercommunicating system, the combination including, a first station having an amplifier, a microphone connected to the input of the amplifier, a receiver, a plurality of normally open station selector switches and communication control switches, a plurality of other stations each having a devic utiiizable both as a receiver and a microphone and each connected to a line leading to one of said communication control switches, and means including a communication control switch and a station selector switch individual to each of said other stations for selectively connecting the devices at said other stations to the input and output of said amplifier and for connecting said receiver to the output of said amplifier when said devices are connected to the input.

14. In an intercommunicating system, the combination including, a plurality of stations each having an amplifier, a microphone connected to the input or" the amplifier, a receiver, a station selector switch and a communication control switch, another station having a device utilizable both as a microphone and a receiver connected to a circuit leading to each of said first mentioned stations, and means including the communication control switch and station selector switch and circuits controlled thereby at each of said first mentioned stations for selectively connecting said device to the input and output of the amplifier at th station and for connecting the receiver thereat to the output of said amplifier when said device is connected to the input.

15. In an intercommunicating system of the type including a plurality of stations each including a receiver connected to an interstation circuit individual thereto, an amplifier, a microphone connected to the input of said amplifier and station selector switches for connecting the output of the amplifier to the circuits individual to the other stations, the combination including a plurality of devices utilizable both as a receiver and a microphone, individual circuits to which said devices are connected leading to said first mentioned stations, separate communication control switches at each of said first mentioned stations connected to each of said last mentioned circuits, station selector switches associated with said communication control switches for connecting the latter to the amplifier output, and means including circuits controlled by each of said communication control switches for selectively connecting the device with which it is associated to the input and output of the amplifier and for connecting the receiver at the station to the output of the amplifier when the device is connected to the input.

16. A unit for use at a station of a multiple station intercommunicating system, including in combination, an amplifier, a microphone connected to the input thereof, a receiver adapted permanently to be connected to an interstation circuit, a circuit adapted to be connected to a second interstation circuit, and means including a switch for selectively connecting the last mentioned circuit to the input and output of the amplifier and for connecting the receiver to the output of the amplifier when the last mentioned circuit is connected to the input.

1'7. A unit for use at a station of a multiple station intercommunicating system, including in combination, an amplifier, a microphone connected to the input thereof, a receiver adapted permanently to be connected to an interstation circuit, a circuit adapted to be connected to a second interstation circuit, and means including a switch for selectively connecting the last mentioned circuit to the input and output of the amplifier and for connecting the receiver to the output of the amplifier when the last mentioned circuit is connected to the input, said last mentioned switch being biased to return to a position wherein said last mentioned circuit is connected to the output of said amplifier.

18. In a unit for use at a. station of a multiple station intercommunicating system and of the type comprising an amplifier, a microphone connected to the input of the amplifier, a receiver adapted permanently to be connected to an interstation circuit individual to the unit, a plurality of station selector switches adapted to connect the output of the amplifier to interstation circuits individual to other units, the combination including, a plurality of circuits adapted to be connected to other interstation circuits, and means including an equal number of normally open switches and circuits controlled thereby for selectively connecting their associated interstation circuits to the input and output of the amplifier and for connecting said receiver to the output of the amplifier when the associated circuits are connected to the input.

19. In a unit for use at a station of a multiple station intercommunicating system and of the type comprising an amplifier, a microphone connected to the input of the amplifier, a receiver adapted permanently to be connected to an interstation circuit individual to the unit, a plurality of station selector switches adapted to connect the output of the amplifier to interstation circuits individual to other units, the combination including, a plurality of circuits adapted to be connected to other interstation circuits, means including an equal number of normally open station selector switches, communication control switches normally connecting associated interstation circuits to selector switches and circuits controlled thereby for selectively connecting the interstation circuits to the output and input of the amplifier, and means including circuits controlled by said communication control switches for connecting said receivers to the output of the amplifier when the interstation circuits are connected to the input.

WAINO M. KOLEHNIAINEN. 

